Construction:
The top hat functions as a method of releasing an infinite number of minecarts at specific time intervals, or very, very fast. It consists of a three by three (3x3) tower, with a hollow one by one center, and no roof. At the base, there are two sections of wall missing. Track and rollers are placed at the center of the base of the tower, extending out from one of the holes. This goes to whatever device you wish to feed with minecarts. The rollers are powered though the other hole. They are connected to either a lever, if you want all the minecarts to go spewing out at once, or a short duration, longer interval
1,
repeater, if you wish to send out one minecart at a regular time interval.
Loading:
Minecarts are fed into the top hat by either a normal dump zone, or a
minecart auto-dump set to accept mincarts. If this is to feed a shotgun, have a 2 tile loading track, set for your desired items, and to push when full, which ends over the open top of the top hat. Then assign a new minecart and start the process over. However you get them in there, the minecarts must be dumped in from the top to load and stack properly.
Refilling:
The minecarts could be collected after being used, and sent back up, and even loaded, via powered spiral ramp. However, if you are always in need of more minecarts, you could put a forge up there, set on repeat. You could also just used dwarven haulers.
Thoughts? Improvements? Uses? All are welcome.
1Meaning that the power is only turned on for a short time, and there is a longer time between those "on-times".